The present invention relates to a method for transferring a web in the reel-up of a paper web. The present invention also relates to a device for transferring a web in the reel-up of a paper web.
A reel change in the reel-up of a paper web is made in a known manner by cutting the web traveling to an old reel being completed and by guiding the web around a new reel spool previously brought into contact with the web and forming the core for a new reel. For performing the cutting and for guiding the web around the new reel spool, air blows are generally used, wherein mechanical cutting of the web in part or in full width can be used as an aid. With thin paper grades, a blow from below the web or from the side of the web is often sufficient to penetrate and cut the web.
The above-described measures are taken during the run when a continuous paper web coming from preceding machine sections is being reeled up, wherein the change sequence is performed each time the reel is completed. Before starting the run with said repeated reel changes, the paper web must be transferred for the first time around an empty reel spool in a so-called turn-up blow. Before the turn-up blow, the web is run in its full width through the reeling cylinder to the pulper. The turn-up blow is executed with an overlying blowing device, a so-called gooseneck, which is brought by a suitable turning mechanism from above down in such a way that the blow nozzle points at the surface of the reeling cylinder, on top of which the web is running to the pulper. The gooseneck is brought to the operating position in such a way that the nozzle points at the surface of the reeling cylinder after a nip between the empty reel spool and the reeling cylinder. The web on the reeling cylinder is torn by the air blow, and air is guided under the web to lift the web to wind up around the empty reel spool. On both sides of the tearing point, the web is torn to the edges, and the new leading end of the web follows the reel spool.
The gooseneck used as the turn-up blow device is relatively complex and requires several pivotal movements, a pressurized air container of its own and its respective valves. Moreover, the gooseneck with its turning mechanisms require space above the reeling cylinder.
It is an aim of the present invention to eliminate the above-mentioned drawbacks and to present a novel method for transferring the web onto the reel spool by the so-called turn-up blow. It is an aim of the method to replace the gooseneck which has been previously used as the turn-up blow device. It is another aim of the invention to make the space utilization in the reel-up more efficient. It is also an aim of the invention to make it possible to select the location of the reel spool more freely in the turn-up blow, because the gooseneck has previously determined the location of the reel spool at least in the respect that the reel spool must have been in a sufficiently high position for the gooseneck to reach around it down below it. The transfer is effected in the invention by an air blow brought from below. Thus, the air blow pipes can be placed in the same structure in which change blow pipes are normally used during reel change sequences. In other respects, the transfer of the web can be fully effected by the same principles and the same auxiliary methods.
It is also an aim of the invention to present a device for transferring the web onto the reel spool. The air channel for effecting the turn-up blow is brought from below to an operative connection with the reeling cylinder. The air channel can be placed in the same structure as the change blow pipes, wherein one or several change blow pipes can be replaced with one or several turn-up blow pipes, respectively, or turn-up blow pipes can be added next to existing change blow pipes. It is also possible to use the same change blow pipes, turnable to a different position than in the change situation, as turn-up blow pipes.